Add users.policies_acknowledged_at

[segiddins]

So we can track when users last acked the policies, and prompt them to do so when we introduce/update them

Signed-off-by: Samuel Giddins segiddins@segiddins.me

[codecov]

Codecov Report

Attention: Patch coverage is 80.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 97.13%. Comparing base (496780c) to head (b08b505).
Report is 188 commits behind head on master.

Files with missing lines	Patch %	Lines
app/models/user.rb	66.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5530      +/-   ##
==========================================
- Coverage   97.14%   97.13%   -0.01%     
==========================================
  Files         453      453              
  Lines        9411     9416       +5     
==========================================
+ Hits         9142     9146       +4     
- Misses        269      270       +1     

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